Various types of electronic files are used to store audio content. As examples, the Waveform Audio file format (WAV) and the Audio Interchange file format (AIFF) and variants thereof are used to store audio data on computing devices. When such files are used on such a computing device, the audio stored in the files is played over a speaker which is typically part of or connected to the computing device. Various types of data files are also used to store electronic content that combines audio content with image and/or video content. When such content is played or otherwise used on a computing device, the audio and displayed content can be provided to a user, in some circumstances simultaneously, for example using a speaker and display monitor that are part of or connected to the computing device.
Whether combined with displayed content or not, audio content can be created, edited, and used by various software applications. For example, a digital audio workstation (DAW) is an electronic system designed to record, edit, and play back recorded sounds and other audio. As another example, Adobe® Premiere® Pro, is a timeline-based editing application that supports both video and audio editing. Adobe Premiere Pro allows a user to create and use one or more audio tracks in a single project that can ultimately be used to create a piece of electronic content combining those tracks. Each track can include one or more audio clips which are typically inserted by the user. Such a user can also adjust volume and other audio settings for each audio track.
Generally, various editing applications allow the creation and use of a sequence of audio tracks and/or clips. For example, in Adobe Premiere Pro, a sequence can be created, displayed, and edited in a timeline panel that shows when each of multiple tracks of a sequence are played with respect to the displayed timeline. Various problems and inefficiencies can occur in existing editing applications in circumstances where audio clips used in a project, sequence, or track do not have the same audio level. For example, in a project for a recording of an interview, the clip of the reporter's voice may be significantly louder than the clip of the interviewee's voice. While there are several methods used to facilitate creating an overall homogeneous loudness level, such methods are generally destructive (undoable but not reversible) because, once used, the underlying audio in the project is changed. Using non-destructive techniques on the other hand, for example, by manually inserting leveling devices such as compressors, requires significant user knowledge and interaction to correctly set parameters and use such features, and often result in unsatisfactory results.